/// <summary>
/// The common code shared by all variants of SetValue
/// </summary>
// Takes metadata from caller because most of them have already retrieved it
// for their own purposes, avoiding the duplicate GetMetadata call.
private void SetValueCommon(
DependencyProperty dp,
object value,
PropertyMetadata metadata,
bool coerceWithDeferredReference,
bool coerceWithCurrentValue,
OperationType operationType,
bool isInternal)
{
if (IsSealed)
{
throw new InvalidOperationException(SR.Get(SRID.SetOnReadOnlyObjectNotAllowed, this));
}
Expression newExpr = null;
DependencySource[] newSources = null;
EntryIndex entryIndex = LookupEntry(dp.GlobalIndex);
// Treat Unset as a Clear
if( value == DependencyProperty.UnsetValue )
{
// Parameters should have already been validated, so we call
// into the private method to avoid validating again.
ClearValueCommon(entryIndex, dp, metadata);
return;
}
// Validate the "value" against the DP.
bool isDeferredReference = false;
bool newValueHasExpressionMarker = (value == ExpressionInAlternativeStore);
// First try to validate the value; only after this validation fails should we
// do the more expensive checks (type checks) for the less common scenarios
if (!newValueHasExpressionMarker)
{
bool isValidValue = isInternal ? dp.IsValidValueInternal(value) : dp.IsValidValue(value);
// for properties of type "object", we have to always check for expression & deferredreference
if (!isValidValue || dp.IsObjectType)
{
// 2nd most common is expression
newExpr = value as Expression;
if (newExpr != null)
{
// For Expressions, perform additional validation
// Make sure Expression is "attachable"
if (!newExpr.Attachable)
{
throw new ArgumentException(SR.Get(SRID.SharingNonSharableExpression));
}
// Check dispatchers of all Sources
// CALLBACK
newSources = newExpr.GetSources();
ValidateSources(this, newSources, newExpr);
}
else
{
// and least common is DeferredReference
isDeferredReference = (value is DeferredReference);
if (!isDeferredReference)
{
if (!isValidValue)
{
// it's not a valid value & it's not an expression, so throw
throw new ArgumentException(SR.Get(SRID.InvalidPropertyValue, value, dp.Name));
}
}
}
}
}
// Get old value
EffectiveValueEntry oldEntry;
if (operationType == OperationType.ChangeMutableDefaultValue)
{
oldEntry = new EffectiveValueEntry(dp, BaseValueSourceInternal.Default);
oldEntry.Value = value;
}
else
{
oldEntry = GetValueEntry(entryIndex, dp, metadata, RequestFlags.RawEntry);
}
// if there's an expression in some other store, fetch it now
Expression currentExpr =
(oldEntry.HasExpressionMarker) ? _getExpressionCore(this, dp, metadata)
: (oldEntry.IsExpression) ? (oldEntry.LocalValue as Expression)
: null;
// Allow expression to store value if new value is
// not an Expression, if applicable
bool handled = false;
if ((currentExpr != null) && (newExpr == null))
{
// Resolve deferred references because we haven't modified
// the expression code to work with DeferredReference yet.
if (isDeferredReference)
{
value = ((DeferredReference) value).GetValue(BaseValueSourceInternal.Local);
}
// CALLBACK
handled = currentExpr.SetValue(this, dp, value);
entryIndex = CheckEntryIndex(entryIndex, dp.GlobalIndex);
}
// Create the new effective value entry
EffectiveValueEntry newEntry;
if (handled)
{
// If expression handled set, then done
if (entryIndex.Found)
{
newEntry = _effectiveValues[entryIndex.Index];
}
else
{
// the expression.SetValue resulted in this value being removed from the table;
// use the default value.
newEntry = EffectiveValueEntry.CreateDefaultValueEntry(dp, metadata.GetDefaultValue(this, dp));
}
coerceWithCurrentValue = false; // expression already handled the control-value
}
else
{
// allow a control-value to coerce an expression value, when the
// expression didn't handle the value
if (coerceWithCurrentValue && currentExpr != null)
{
currentExpr = null;
}
newEntry = new EffectiveValueEntry(dp, BaseValueSourceInternal.Local);
// detach the old expression, if applicable
if (currentExpr != null)
{
// CALLBACK
DependencySource[] currentSources = currentExpr.GetSources();
UpdateSourceDependentLists(this, dp, currentSources, currentExpr, false); // Remove
// CALLBACK
currentExpr.OnDetach(this, dp);
currentExpr.MarkDetached();
entryIndex = CheckEntryIndex(entryIndex, dp.GlobalIndex);
}
// attach the new expression, if applicable
if (newExpr == null)
{
// simple local value set
newEntry.HasExpressionMarker = newValueHasExpressionMarker;
newEntry.Value = value;
}
else
{
Debug.Assert(!coerceWithCurrentValue, "Expression values not supported in SetCurrentValue");
// First put the expression in the effectivevalueentry table for this object;
// this allows the expression to update the value accordingly in OnAttach
SetEffectiveValue(entryIndex, dp, dp.GlobalIndex, metadata, newExpr, BaseValueSourceInternal.Local);
// Before the expression is attached it has default value
object defaultValue = metadata.GetDefaultValue(this, dp);
entryIndex = CheckEntryIndex(entryIndex, dp.GlobalIndex);
SetExpressionValue(entryIndex, defaultValue, newExpr);
UpdateSourceDependentLists(this, dp, newSources, newExpr, true); // Add
newExpr.MarkAttached();
// CALLBACK
newExpr.OnAttach(this, dp);
// the attach may have added entries in the effective value table ...
// so, update the entryIndex accordingly.
entryIndex = CheckEntryIndex(entryIndex, dp.GlobalIndex);
newEntry = EvaluateExpression(
entryIndex,
dp,
newExpr,
metadata,
oldEntry,
_effectiveValues[entryIndex.Index]);
entryIndex = CheckEntryIndex(entryIndex, dp.GlobalIndex);
}
}
UpdateEffectiveValue(
entryIndex,
dp,
metadata,
oldEntry,
ref newEntry,
coerceWithDeferredReference,
coerceWithCurrentValue,
operationType);
}
